#include "ros/ros.h"

int main(int argc, char *argv[])
{
    ros::init(argc, argv, "change_ngcolor");
    // ros::param::set("/turtlesim/background_r", 0);
    // ros::param::set("/turtlesim/background_g", 0);
    // ros::param::set("/turtlesim/background_b", 0);
    // ros::NodeHandle n("turtlesim"); //命名空间
    // n.setParam("background_r", 255); //这里就相当于把上面的turtlesim和这里的接起来，
    // n.setParam("background_g", 255);
    // n.setParam("background_b", 255);
    ros::NodeHandle n; 
    n.setParam("/turtlesim/background_r", 255); 
    n.setParam("/turtlesim/background_g", 50);
    n.setParam("/turtlesim/background_b", 255);
    return 0;
}   